Gear-tooth-chamfering machine



March 4, 1930- I c. E. HAMILTON 49,580

GEAR TOOTH CHAMFERING MACHINE Filed April 14, 1928 4 Sheets-Sheet l Z 34 1 1 a. I 3 J/ 41 Q (D 0 v 91 i 0 30 9 L as if a1 J6 I gwuentoc 'barlesfi. Hamil Z012,

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- GEAR TOOTH CHAMFERING MACHINE Filed April 14, 1928 4 Sheets-Sheet 2 T Charleaifiamillan March 4, 1930. c HAM|LTQN 1,749,580

GEAR TOOTH CHAMFERING MACHINE Filed April 14, 1928 4 Sheets-Sheet 3 60 z 6'6 Z5 r I w .5 #5

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Quorum s Patented Mar. 4, 1930 ylUNITED STATES PATENT OFFECE CHARLES E. HAMILTON, OF RICHMOND, INDIANA, ASSIGNOR TO AUTOMOTIVE GEAR WORKS, INC.,'OF RICHMOND, INDIANA, A OORPORATION OF DELAWARE GEAR-TOOTH-GHAMFERING MACHINE Application filed April 14, 1928. Serial No. 269,882.

rear, or force-receiving, corners ofthe driven gear teeth be accurately chamfered or dubbed ofl so that the driving force of the pinion, which at the moment of engagement with the stationary gear is moving both axially and angularly, will be most effectively applied to the stationary gear and will not operate to damage the teeth of either gear by a swaging action.

The object of my present invention is to produce a mechanism by means of which the desired chamferingv of the teeth may be accomplished efliciently, economically and accurately.

The accompanying drawings illustrate my invention.

partial vertical section, of the side opposite 30 that. shown in Fig. 1 Fig. 4, a front elevation, with parts broken away ;'Fig. 5 a vertical sec tion through the gear holder and adjacent parts; Fig. 6 a transverse vertical section through the cutter head; Fig. 7 a sectional detail of the means. for reciprocating the clamping head; Fig. 8 an axial section through the cutter-shaft cavity; Fig. 9 a fragmentary plan of a portion of a gear being operated upon, the cutter and the indexing abutment, and Fig. 10 a side elevation of the cutter and a section of a tooth being operated upon.

In the drawings 20 indicates a suitable supporting base upon which is mounted a horizontally slidahle work-receiving carriage 21 suitably guided and reciprocated through a comparatively short stroke by any suitable means for instance as the cam 22 (Fig. 7 rotatably mounted in the carriage and engaging a roller abutment 23 carried by the base 20.

J ournalled on a vertical axis on carriage 21 is a gear receiving head 24 formed at its upper end, at 25, to receive any one of a series of annular adapters 26 each of which is provided at its upper outercorner with a gear seat 27 sized to receive a gear 28 the teeth of which are to be chamfered. A dished clamping plate 29 is provided to engage the gear 28 and is firmly clamped in place by means of the clamping nut 30.

Head 24 is advanced rotatively step-bystep, to bring the teeth of gear 28 successively into position to be operated upon, by means of a pawl'31 urged toward the gear by means of a spring 32 and supported on a block 33 which is adjustable toward and from the periphery of the gear in a guide 34, the arrangement being such that, during each outward stroke of carriage 21, the gear is advanced one tooth. As the carriage 21 moves forwardly toward the cutter under the action of cam 22, the gear 28 is brought into engagement with an indexing tooth 38 on a block removably attached to an arm 39 carried by a rock shaft 40 which is biased toward the gear 28 by a spring 41, so that the gear 28 is firmly held against rotation during the further portion of the forward movement of carriage 21.

Cam 22 is preferably so formed that it will cause a fairly rapid initial forward movement of the carriage 21 toward the cutter to bring the gear 28 into engagement with the indexing tooth 38, and will then cause a further but slower forward movement of the carriage 21 toward the cutter during which the cutting is threaded through a support 43 (Fig. 6) n and held by the temper screw 44, the arrangement being such that each tooth of gear 28 may be accurately positioned prior to, and firmly held during, the cutter operation. Shaft 40 is most conveniently carried by head 61 which will be described later.

The desired chamfering operation is accomplished by means of a cutter 50 having cutting teeth of the milling cutter type, active at the periphery 51 and also at a flat face 52 at right angles to the axis. Cutter 50 is set at such angle and position relative to the axis of gear 28and the line of lateral movement of that axis produced by the reciprocation of carriage 21, that the cutting face 52 of the cutter will form the chamfered face 53 which is desired on the teeth of gear 28, and, as the angle of this face to the center line of the gear tooth, and the width of the unchamfered end face 54 may need to be different in different gears, means is provided to obtain the desired adjustment.

Cutter 50 is nonrotatively secured on'the lower end of a cutter shaft 55 by means of a nut 56 so formed, as shown in Figs. 8 and 9,

that it will not contact with any portion of the teeth of the gears 28 which are to be operated upon. Shaft is journalled in a bearing bracket 57 and is angularly adjustable therewith about the axis of the pinion 58 by means of the slotted clamping means 59. Bracket 57 is supported on a plate 60 and this plate is supported on a laterally adjustable head 61. Plate 60 is angularly adj ustable on head 61 about the axis of the drive shaft-62, by means of clamping bolts 63 and this plate forms a support for the pinion 58 which meshes with a pinion 65 on shaft 55 and a pinion 66 on shaft 62.

Parts 57 and 60 form a bracket or support by means of which the cutter shaft 55 may be adjusted about the two axes of gears 58 an'd'62. Cutter 50 may, therefore, be set at any desired angular position relative to the plane of reciprocation of carriage 21 and also at any desired lateral offset relative to the medial line of reciprocation of carriage 21, and may thus be properly set to produce a desired chamfer on the teeth of gears 28, without interferring with the driving connection with the shaft 62. Shaft 62 is driven from any suitable source of-power through be driven with a gear 7 6 carried by pulley 69 and sup:

ported in a yoke 77 on head 61 so as to partake of the adjustment movements thereof, to be described later. Gear is splined on a shaft 80 which is journalled in carriage 21 parallel with its line of reciprocation and provided with a pinion 81 connected. by a reducing gear train 82, to the shaft 84 which is also journalled in'carria-ge 21 and carries cam 22, the arrangement being such that, While the cutter 50 is rotated at a comparatively high rate of speed, the carriage 21 may be reciprocated at a comparatively low rate of speed which may be coordinated with i The principal point to note is that the cutter speed, as well as the speed of cutting or formation of the chamfer is wholly independent of the size of the teeth of the gear 28 which is to be operated upon, is wholly independent of the pitch of those teeth or the size of the gear and is independent of any rotation of gear 28 I This is exceedingly important and makes possible chamfering operations at very much greater speeds and with a very much greater efficiency and of much better quality than has heretofore been possible.

Instead of changing cam 22 for different sizes of teeth to be operated upon, it is much more convenient to adjust the head 61 toward and from carriage 21. Head 61 is, therefore, slidably mounted in suitable ways in base 20 and adjusted by a temper screw 91 (Fig. 1) and clamped in adjusted position by bolts 92. V

Cutter .50 is preferably rotated, as'indi; cated in Fig. 9, so as to have an upwardcutting action on the teeth of the gears 28 and,

because the rotative-spee'd of this cutter may be veryhigh, it is apparent that the feed of the carriage toward the cutter may be correspondingly high without choking the cutter or causing chattering. It will also be apparent that the cutting action is of such character that the cutter will not become readily dulled and that the teeth of the cutter need not be subjected to heavy stresses in order to attain rapid cutting action, due to the fact that the speed of rotation of vthe cutter is not in any way dependent upon the pitch of the gears 28 to be operated uponor upon any rotation of said gears28.

The T-slots into which the heads or the 7 .bolts 63 take are endless so that the plate 60 may be shifted to reverse the angle of shaft 7 50 relative tothe plane of gear 28 so that a rear entry chamfer may be out if desired.

I claim as my invention: I

1. A machine for chamfering gear teeth, comprising a holder for the gear to be operated upon, a cutter-shaft-carrier adjustable about two axes, each at anangle to the axis of the holder, a cutter shaft mounted forrotation in said carrier about an axis at an acute angle to the plane of such gear when so held 3. A machine for chamfering the formed teeth of a gear, comprising a main body, a

' and at an acute angle relative to said axis,

means for automatically causing successive relative lateral oscillatory movements between the axis of the gear and the axis of the cutter shaft whereby the cutter may have successive cutting actions upon successively presented teeth of the gear beginning at the tip of the tooth and proceeding toward its root, means by which the cutter may be rotated independently of angular movement of the gear, and means for automatically advancing the gear angularly step by step between successive cutting operations.

4. A machine of the character specified in claim 3, wherein the cutter shaft is carried by a support angularly adjustable about two parallel axes which lie substantially parallel with the line of relative lateral movement between the axis of the gear and the axis of the cutter shaft.

5. A machine for chamfering previously formed teeth of a gear, comprising a main body, a gear-receiving carriage reciprocably mounted on said main body, means carried by said carriage for supporting a gear and permitting step by step angular adjustment thereof, means for automatically reciprocating said carriage in a plane approximately at right angles to the axis of the gear support, means coordinated with said reciprocating carriage for automatically advancing the gear angularly step by step, a cutter shaft arranged in a plane laterally offset from the axis of the gear and at an acute angle to said gear axis, and means by which said cutter shaft may be rotated independently of angular movement of the gear, the arrangement being such that the cutting action of the cutter upon the teeth of the gear will be in itiated adjacent the tips of the gear teeth and proceed toward the roots thereof.

6. A machine of the character specified in claim 5 wherein the cutter shaft is journaled in a support independently angularly adjustable about two laterally separated axes which are substantially parallel with the plane of reciprocation of the gear carriage.

- In witness whereof, I, CHARLEs E. HAMIL- TON, have hereunto set my hand at Richmond,

Indiana, this 11th day of April, A. D. one

thousand nine hundred and twenty-eight.

CHARLES E. HAMILTON. 

